Manufacture of artificial filaments, threads, films, or the like



133124,1934.I A SAWLCH. 1,933,330

MANUFACTURE OF ARTIFICIAL FIIJAMENTS, THREADS, FILMS, OR THVE LIKE Dec. 4, 1934. s. A. WELCH 1,983,330 MANUFAGTURE OFYARTIFICIAL FILAMENTS, THREADS, FILMS,v 0R THE LIKE Fil-ed June 27, 1929 2 Sheets-Sheet 2 Patented Dec. 4, 1934 PATENT OFFICE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FILMS, 0R THE LIKE Sidney Arthur `Welch, Spondon, near 'Derby, England, assignor to Celanese Corporation of America, a corporation of Delaware Application J'une 27, 1929, serial No.`374,'1ss In Great Britain July 6, 1928 1o claims.

This `invention relates to the manufacture of filaments, threads, films or the like by the eX- trusion of` solutionsof cellulose or of cellulose derivatives through spinning jets, nozzles or other extrusion orifices; Whether such filaments,

threads, lms or the like are made by the wet coagulation method or by the dry or evaporative method of formation.

According to the invention, I cause the solution of cellulose or of the cellulosederivative or derivatives to pass immediately prior to-passing through the spinning jets or other extrusion orifices through a number of substantially parallel capillary passages (i. e. tubes,y channels or the like) so arranged as to be substantially parallel to the line of flow taken by the solution on leaving the same.

The present invention enables the production of highly satisfactory threads, filaments, films or the like. Owing to the very efficient *filtering action of the capillary tubes, channels or the like the clarity of the extruded products is of a very high order, which is especially important in the manufacture of films. Further the invention enables the production of filaments, threads, films or the like of improved strength and other physical properties, which improvement may possibly be dueto the highly efiicient filtration effected by the capillary tubes, channels or the like and possibly also to said tubes, channels or the like effecting in:l considerable measure a parallelization ofthe constituent particles of cellulose or cellulose derivative in the solution land. enabling said particles to be coagulated to a large extent in regular and parallel `order Yin the formation of the lilament, film or the like.,

For the purposes of the invention I may employ any suitable device or member formed or provided Withthe aforesaidcapillary'tubes, channels or the like; and said members or devices may be constructed from any suitable material and in any suitable manner. ployinentvvith solutions of cellulose acetate or other cellulose derivatives in volatile solvents, the said members or devices may conveniently be formed from one or more transverse sections of cane, which sections may if desired be pretreated in any suitable manner toiemove waxes or other natural impurities and which sections may if desired be soaked, prior to use, in the solution of the cellulose derivative until any swelling therein has'attained the maximum. Or for instance the said members or devices may be formed from one or more plates of metal, bakelite or other suitable material moulded with or drilled-'With a number For instance, for em-` `o'ffveryfine. and closely adjacent holes. It will of course be understood that said members or devices should not be made of materials liable to attack by the solution to be extruded, for instance When extruding solutions of cellulose or of cellulose derivatives containing cellulose solvents v(e.' g. 'cuprammonium solutions, viscose solutions, solutions of cellulose or cellulose derivatives containing thiocyanates or the like) said members or devices `should be made from metal or other resistant material and not from cane or other form of cellulose.

In performing the invention I arrange the said members or devices near to, or it may be even in `contact with, the spinning jets or other eX-''zo trusion orices. For instance the member or device may be fitted very close to the jets or orifices (e. g. at a distance of about 1 mm. from the jet plate) in which case I preferably interpose a thin distance piece (e. g. a stamped or 3.75 drilled disc or a piece of fine Wire gauze) between the member or device and the back of the jet plate. Or for instance the member or device mayvv be'iitted to contact with the back of the jet plate, in Which case the jets or orifices may be'i'go flared or countersunk on the side in contact With the'member or device to ensure the jets or oriiices receiving adequate supply of fluid from the capillaries (of thev member or device) communicating therewith.

I preferably rcause the solution of the cellulose or cellulose derivative or derivatives to pass through one or more filtering devices (for instance one or more 'cotton or like filters) prior to passing through the capillary tubes, channels '90 or the like of the members or devices.

The solution to be extruded may if desired be caused to pass successively through a series of the said capillary tubes, channels or the like prior to passing through the set of said capillary tubes or channels which immediately precede the spinning jets or other extrusion orifices; for instance successively through one or more transverse sections of cane, the capillary tubes or channels of which are arranged substantially parallel to the. line of flow of the solution prior to passing through a like section of cane immediately preceding the spinning jet or other extrusion device, and thence through the spinning jet or jets or other extrusion orifices.

For the purpose of the invention I preferably employ capillary tubes, channels or the like Which are very much smaller than the diameter of the orifice through which the solution is to be extruded, forinstance in the spinning of artificiali-110 silk I may advantageously cause the solution to pass through capillary tubes, channels or the like of from about 1/5 to about 1/50 of the diameter of the spinning orice; and similarly fine capillary tubes, channels or the like are highly useful in the extrusion of films, strips and the like irrespective of the aperture of the eX- trusion jet or orifice.

The accompanying drawings serve to illustrate `or similar volatile solventnothaving asolvent action i on .the cane.

lZ-teferring-to -IEiguresv 1,2:and 3. rFigure l is `a sectional'view showing `the transverse-section .of-cane fitted'in thelower partof a candle or Vfilter containing member which terminates the supplyV pipe tovvhich the spinning-jet or Ynozzle 'FigurexZis a'view cf the sectionvof cane andthe spinning jet or nozzle on a'larger scale; whilstFigure-S is a'planview onthe line cA-B-.Figure y2.

In :Figures l, 2 and 3, 1.is the body of the candle or lter containing-member `:forming the cylindrical ffiltercontaining cham- `ber 2, which terminates .the supplypipe to the spinning jet or nozzle. and to which the spinning :jet or nozzle 3 isattached; the member 1, shown zbrokeniaway, being attachedto the supply pipe,

not shown. The spinning jet or nozzle`3 is formedzfroma cupped plate-Aprovided vvith` ex- .trusionforices sandis fitted With'a transverse section of 'cane 6 so arranged that the capillary tubes or channels 7 thereof are substantially parallely tothe axes of the orifices `5 of the jet "or...nozzle.`3. IBetWeen theupper-ia'ce of the jet ornozzle Sand ythebase of the section of cane 6 is fittedfaLthin plate (eg. about l thick) `43 provided Withholes 9, the plate 8 being. arranged 'so `that the holes -9 are. in register with the orifices 5.' of the spinning jet or nozzle. 3. rThe holes 9 are considerably larger than the orices 5 (e. g. 50.v or*v more times the diameter of the orices 5) toensure the jets 3 receiving adequate supply .of the spinning solution. from the capillary tubes or-zchannels '7 in :communication therewith. A lter. 10 (composedof .a number of layers of ne calico or the like) is placed on the top of the section of'cane 6. .The nozzle-3, plate 8section of-cane'andlter 10 are secured to the :screwed end of themember.Y by the .annular ring or member 1l,..packing Washers 12 and 13 being interposed, vin the manner shown, respectively betvveenlthe lovver'end of the member l and the lter l0 and between the nozzle and the member Vl1. erably-treated; prior to .use,'with a solvent or sol- 4The transverse'section of cane 6 is prefvents toremove Waxor other soluble impurities,

. Aforinstance it'may bev treated first with'xylene yandf then with acetone to remove'the Wax yand .soluble vimpurities-as f arcas possible.

1t is preferably also subjected to treatment With 'the artificial silk-spinning solution envisaged until 1 any' svvelling therein fhas attained -substantially "the maximum. iWhilst the section of cane may `befcomposed of'anyy cane having substantially parallelcapillarytubes or channels `I prefer to use a section of cane having capillary tubes or channels of substantially the same cross-section as each other and having capillary tubes or channels of from about 1/5 to about 1/50 of the diameter of the spinning orifices.

Within the chamber 2 is provided a lter member 14 comprising a perforated pipe or the like V15- which is attached to the supply pipe (not shown) and which is Wound With a number of layers 16 of fine cotton, calico or the like.

suming the y.apparatus to be spinning, the spin- `nin'gsolution (e. g. a solution of cellulose acetate in acetone) .passes `from the supply pipe (not shown) tothe interior of the filter member 14,

thence `,laterally through the perforated Walls of the pipe orthe like l5 and filter layers 16 to the ,chamber 12. From-the chamber 2 the solution passes-viathe bore 17 through the lter 10. The

.solutionipasses thence through the capillary tubes or channels '7 of the section of cane 6 and the holes-Q-ofthe plate `8 tothe spinning-orifices 5. From the orifices 5 thespinning solution passes toty a. heatedspinning cell or `metier wherein -the articial silk filaments are formedlin thelniovvn manner.

A Referring to :Figures v4 and 5, Figure-4 issa front ,sectional view showingthe transversesection of cane tted to thel lovverfpartzof acandle ornlter containing device-Which terminates the supply pipe to vvvhich the-extrusion jet` or nozzle,-Jy

isiitted, Figure 5isa sidesectional vievv of the apparatus shown `in Figure 4. ,In Eigures -4 ,and 5, 1 is the body of the candle or filter containing member forming the filter containing lcham- Vber. 2-which terminates the supplypipe to which,V

the extrusion-jet or.nozzle orifice and-to which the extrusion jet or nozzle 3 is attached; fthe -member 1, shown brokenv away, Abeing attached tothe supplypipe,-not-shown. The extrusiont-jet ,ornczzle Bis for-med with ain-extrusion orice 4V and.V is ntted with. a transverse section of A cane 5 so. arranged that the capillary tubesor channels 6 thereof ,are substantially parallel -to ,the line .of .owvof the uid through the-,orifice 4. The ,jet or nozzle 371s formed withia V Vshaped channel l opening into the orifice-,4,rthis channelbeing .provided to ensure an adequate supplyY ofthe fluid `reaching the oriflce4, from the capillary tubes or channels 6. A filter 8 (composedvof -a-numberof. layersof line calicoor the like) is placedon top ofthe section of cane 5'and the nozzles,

section of cane 5and filter Sisecured tof theend ot the member 1 by means of theangle. pieces 9 `and 10, rpacking washers 11 and 12 being fitted respectively-*between the4 filter Band the end-of the member 1 and betvveenthenlterf` andthe top of the jet 3. The transverse section of cane `Fris exactly: similar to that described-with reference to Figures 1 to 3 except ofcourse-in--regard to actual shape. f

-Withinthe chamber 2 is provided a lter. mem- `ber 13 comprising a perforated pipe114,-Which is f attached to the supply pipe (not shown) and yvvhicliis Wound with anumber oflayers-lof `fine cotton, calico or the like.

.Assuming the` apparatus to be extruding a nlm, the-solution (e. g. a solution of cellulose acetate -in acetone) passes fromfthe supplypipey(not shown) tothe interiorY of the filtermember 13, thence llaterallyV through theV perforated walls of the pipe 14 and filter layers 15` to the-chamber. 2.

From the chamber 2 the solution passes via the bore 16, through the filter 8. The solution passes thence through the capillary tubes or channels 6 of the -section of cane 5 andvia the channel 7 to the extrusion orifice 4. From the orifice 4 the solution passes to a heated chamber (or to a coagulating solution) wherein the film is formed in the known manner.

What I claim and desire to secure by Letters Patent is:-

1. Process for the manufacture of filaments, threads, lms or the like by the extrusion of solutions of cellulose or of cellulose derivatives through orifices, characterized in that said solutions substantially immediately prior to passing through the orifices are caused to assume the form of a number of substantially parallel capillary streams substantially parallel to the line of flow taken by the solution thereafter.

2. Process according to claim 1 and wherein the capillary streams are substantially uniform in cross-section and have dimensions of from 1/5 to 1/50 of the diameter of spinning orifices commonly employed for the manufacture of artificial silk.

3. Process for the manufacture of artificial filaments, threads, films or the like by the extrusion of solutions of cellulose or of cellulose derivatives through extrusion orifices, characterized in that the said solutions are filtered and subsequently substantially immediately prior to passing through the extrusion orifices, are caused to assume the form of a number of substantially parallel capillary streams substantially parallel to the line of flow taken by the solution thereafter.

4. In a process for the manufacture of filaments, threads, films or the like by the extrusion of solutions of cellulose or cellulosic derivatives through extrusion orifices, the step of effecting a parallelization of the constituent particles of the solutions substantially immediately prior to the passage of the solutions through the extrusion orifices.

5. In a process for the manufacture of filaments, threads, films or the like by the extrusion of solutions of cellulose or cellulosic derivatives through extrusion orifices, the step of simultaneously filtering said solutions and effecting a parallelization of the constituent particles of the solutions substantially immediately prior to the passage of the solutions through the extrusion orifices.

6. Apparatus for the manufacture of filaments, threads, films or the like by the extrusion of solutions of cellulose or cellulose derivatives, comprising an extrusion nozzle provided with one or more extrusion orifices, a member fitted behind .and in close proximity to said nozzle and provided with a number of substantially parallel longitudinal capillary passages arranged substantially parallel to the line of flow taken by the solution to the extrusion orifice or orifices.

'7. Apparatus according to claim 6 and wherein the said member is fitted to the extrusion nozzle directly behind the extrusion nozzle, a thin distance piece being interposed between the said member and the feed side of the extrusion orifice or orifices.

8. Apparatus according to claim 6 for the manufacture of films and wherein the said mem- 100 ber is fitted to the extrusion nozzle near to the feed side of the extrusion nozzle and separated from said orifice by a V-shaped chamber the narrower end of which communicates with the extrusion orifice.

9. Apparatus according to claim 6, and wherein said member is formed or provided with capillary passages of substantially uniform cross-section and of dimensions of 1/5 to l/50 the diameter of spinning orifices commonly employed in the 110 manufacture of artificial silk.

10. Apparatus according to claim 6, and wherein a transverse section of cane is employed as the said member.

SIDNEY ARTHUR WELCH. 

